Vehicle recall 79V137000 · June 1, 1979

Mack RWL, RWS and 2 more models

The pitman arm retaining nut may not have been torqued to manufacturer specifications.

Source: NHTSA data as of September 22, 2026. Last refreshed Sep 23, 2026, 2:43 AM UTC.

Summary: The pitman arm retaining nut may not have been torqued to manufacturer specifications. This could result in inadequate retention of the nut at the output shaft, allowing the pitman arm to become loose.
Remedy: Dealer will inspect and retorque pitman arm, if necessary, at no cost to owner.
Notes: Vehicle description: trucks.system: steering linkages; arm, pitman.consequences of defect: this condition could lead to premature wearing of theoutput shaft causing loss of vehicle control and an accident.

Recall details

NHTSA campaign: 79V137000
Reported to NHTSA: June 1, 1979
Filed by: MACK TRUCKS, INCORPORATED
Owner notification: October 22, 1979
Vehicles potentially affected: 6,673
Initiated by: the manufacturer
Components: Steering › Linkages

Recall 79V137000 on nhtsa.gov, with the manufacturer’s documents

Vehicles covered

As listed by NHTSA. A recall usually covers only some vehicles of each model and year, often a production date range.

Mack RWL (1977-1979): 1979, 1978, 1977
Mack RWS (1977-1979): 1979, 1978, 1977
Mack WL (1977-1979): 1979, 1978, 1977
Mack WS (1977-1979): 1979, 1978, 1977

Has your Mack been repaired?

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